30 CFR 75.1002 : Mineral Resources (§ 1.1 To Parts 1291-1299) — (§ 1.1 To Parts 105-199) — Mine Safety And Health Administration, Department Of Labor (§ 1.1 To Parts 105-199) — Coal Mine Safety And Health (§ 70.1 To § 90.301) — Mandatory Safety Standards - Underground Coal Mines (§ 75.1 To § 75.1916) — Trolley Wires And Trolley Feeder Wires (§ 75.1000 To § 75.1003-2) — Installation of electric equipment and conductors; permissibility.

(a) Electric equipment must be permissible and maintained in a permissible condition when such equipment is located within 150 feet of pillar workings or longwall faces.

(b) Electric conductors and cables installed in or in by the last open crosscut or within 150 feet of pillar workings or longwall faces must be -

(1) Shielded high-voltage cables supplying power to permissible longwall equipment;

(2) Interconnecting conductors and cables of permissible longwall equipment;

(3) Conductors and cables of intrinsically safe circuits; and

(4) Cables and conductors supplying power to low- and medium-voltage permissible equipment.

(5) Shielded high-voltage cables supplying power to permissible continuous mining machines.